Field of Invention
The present invention relates to an electrical connector structure. More particularly, the present invention relates to an electrical connector that is capable of adjusting high-frequency signal transmission.
Description of Related Art
With the rapid development of technology, the amount of data transmission increases accordingly, and thus conventional transmission devices cannot meet the current high efficiency requirements. An early Small Computer System Interface (SCSI) has been modified to become a current Serial Attached SCSI (SAS) which has broken through the upper limit of the original transmission speed. The SAS technology continues to improve in research and development, and thus the transmission speed is increased to 24.0 Gbps, in which the SAS technology that supports and is compatible with Serial Advanced Technology Attachment (SATA) has a common and wide range of advantages.
In order to achieve the convenience of portability and to meet the requirements of thinness and shortness, components are designed to be miniaturized, and an electrical connector tends to be smaller. In order to prevent serious signal attenuation, a signal source transmits messages at a higher frequency band when the electrical connector is in the process of signal transmission. Due to the miniaturization design of the electrical connector, gaps between adjacent terminals transmitting signals are greatly shortened. Because transmitting signals at use the high-frequency frequency band, the two adjacent terminals are highly susceptible to mutual high-frequency noise interference, such as cross talk, impedance, propagation delay, propagation skew, and attenuation, thus causing the signal transmission process to be distorted or have errors, greatly reducing the transmission efficiency of the electrical connector.
In order to overcome the interference problem between the terminals, various connectors on the market are designed with metal grounding parts, in which the metal grounding parts are formed by stamping and bending, and are disposed in the connector. To reduce high-frequency interference between the signal terminals, grounding terminals are connected by the metal grounding parts. However, contact surfaces between the metal grounding parts and the grounding terminals may have gaps or different surface areas, thus resulting in poor grounding effects. In addition, the metal grounding parts require additional manufacturing processes, thus increasing the manufacturing cost and the production time. Therefore, these conventional connectors still need to be improved.
U.S. Pat. No. 9,281,589 provides a solution. Referring to FIG. 9, this patent reference discloses a connector A. The connector A includes terminals C and an insulation casing E. The insulation casing E includes an upper side wall E1, a lower side wall E2, and a chamber E3 which is sandwiched between the upper side wall E1 and the lower side wall E2, in which a groove B is formed on an outer surface of the upper sidewall E1 located away from the chamber E3, and the groove B has through holes B1 that pass through the upper sidewall E1 and expose grounding terminals. A conductive glue D is injected into the groove B. The conductive glue D fills the groove B and the through holes B1, and contacts the ground terminals of the terminals C until the conductive glue D is cured and shaped conformal the shape of the groove B and the through holes B1, and the conductive glue D has bumps D1. The bumps D1 of the conductive glue D and the grounding terminals electrically connected to each other making the grounding terminals are electrically shorted to each other, so as to improve high frequency interference of the connector A.
It can be seen from the above description that the conductive glue D is disposed on the outer surface of the insulation casing E located away from the chamber E3. The method of fixing the conductive glue D is to fill the groove B with the conductive glue D in a liquid state, and when the conductive glue D is cured, the conductive glue D is adhered to the groove B. The material composition of the insulation casing E is different from that of the conductive glue D, and the conductive glue D is fixed on the surface of the insulation casing E after the insulation casing E is formed. Because the groove B and the through holes B1 in the insulation casing E do not have designs for preventing the conductive glue D from falling off, the conductive glue D is very likely to fall off from the surface of the insulation casing E after the connector A has been used for several times, thus causing the connector A to have an incomplete structure which affects the quality and stability of signal transmission.
Since the conventional connectors have the defects affecting the transmission quality when the high-frequency signal is transmitted and cannot meet the actual industrial requirements, in order to improve the transmission quality and maximize the efficacy of the connector, an improvement for the structure of the connector design to solve the problem is greatly needed.